The collection of Crow pellets continues in and around the winter crow roost in Lawrence, MA. It is fascinating to look back at a pellet collection effort from last December in the same location. About 125 pellets were gathered into a number of larger zip lock bags. Each bag with collected pellets was dated. Once a sufficient number had been collected for a statistically relevant sample size, the pellets were sent off for analysis. The pellets had been collected form a truck depot parking lot adjacent to the overnight crow roost. The crows spend a great deal of time on the ground in this location. From prior studies, we have learned that the crows will typically eject pellets hours after feeding. Here is a photo of a tray of crow pellets gathered this year to provide an idea of what they look like.
From Tom French last winter: here is an initial draft of an analysis of the contents of the crow food pellets collected in Lawrence, MA in December 2017. Regurgitated crow pellets collected by Craig Gibson in December 2017 (N=~125). Food items were identified by T.W. French.
About 95% by volume of the pellets was made up of Asian Bittersweet (Celastrus orbiculatus) berries. About 15 pellets (11.5%) included at least some food items other than Asian Bittersweet berries. These other food items included the following:
Large white seeds – 25 (about half are safflower seeds, the other species is not yet determined)
Corn – 8 fresh (soft) kernels from 1 pellet
Cantaloupe or Honey Dew Mellon – 3 seeds
Sunflower – 1 seed
Acorn – 1
Mouse – 2 individuals of 2 species (1 is Peromyscus leucopus, 1 is not yet determined)
Medium-size mammal – 22 bone fragments (squirrel/rabbit? Probably road-killed)
Songbird – 1
Saltmarsh Snail, Melamppus bidentatus – 1 (4 mm)
Beetle – 1
MacDonald’s ketchup package
Plastic wrap – Small piece of thin white plastic wrap similar to that placed underneath meat in a
grocery meat package.
Small stones – Many small pieces of rock, concrete, and asphalt probably picked up with food
Glass – 3 small pieces (1 blue, 2 clear), probably picked up by accident.
Grass stems – several small fragments, probably picked up by accident.